20 Kilometers (1 Mile Above Sea Level) - Seth James DeMoor

Aug 13, 2025

Intro: This is a quick summary of “20 Kilometers (1 Mile Above Sea Level)” from Seth James DeMoor. It’s a great watch — we’re breaking it down so you can try the workout today. Be sure to check out the full video for all the details.

Key Points:

Pacing by feel: After a quick glance at the watch during the first 1‑1.5 km of a threshold run, cover the watch (or tape it) to force yourself to run by feel. This builds confidence and reduces reliance on the watch.
The “art of the pivot”: Be ready to adjust the workout (or even move it to another day) when weather or terrain changes (ice, snow, heat). Flexibility prevents missed workouts and protects sleep/recovery.
Consistency over volume: “Aerobic bank deposits” – easy miles build the aerobic engine and let you increase weekly mileage without injury. Consistency beats occasional high‑volume spikes.
Watch‑glance rule: For long threshold runs, look at the watch only 2‑3 times in the first 1500 m, then rely on perceived effort. For a 13‑mile run, aim for ~10 glances total (roughly every 1.5–2 miles).
Threshold workout: 20 km at threshold pace (≈5:21 min/km, about 12.4 mi). Splits (minutes:seconds) were roughly: 5:16, 5:17, 5:16, 5:14, 5:17, 5:21, 5:23, 5:24, 5:28, 5:24, 5:28, 5:25, 5:24. Average pace reported as 5:21 min/km (≈8:34 min/mile). Average heart‑rate and power were also recorded.

Workout Example:

20‑km Threshold Run (≈12.4 mi / 20 km)
- Warm‑up: 10‑15 min easy jog + dynamic leg work.
- Main set: 20 km at steady threshold pace (~5:21 min/km). 
  • Goal: stay in the aerobic zone, feel steady effort.
  • Glance at watch only 2‑3 times in the first 1.5 km, then rely on feel.
- Cool‑down: 10‑15 min easy jog + stretch.

Feel free to adjust the target pace to match your current threshold (use your recent race pace or recent 5‑k pace as a guide). The key is to stay comfortable, maintain a steady effort, and practice the “watch‑cover” technique.

Closing Note: Give this 20 k threshold run a try, tweak the paces to fit your own training, and log it in the Pacing app to track your progress. You’ve got this—run with confidence and keep building those aerobic “bank deposits”! 🚀